Global Entry or Nexus?

I'm trying to figure out which to choose.

I do a lot of air travel so TSA Precheck is important, but I also want the advantages of checking into Canada without having to go to the customs check in point.  I want to be able to call in instead of physically checking in.  I realize occasionally I may have to physically check in.

Both will get me TSA Precheck, but it doesn't look like Global Entry helps with marine customs.

Does anyone have experience with either of these options?

Global Entry is $100

Nexus is $85

Charlie Soffel